"Lace has never been done before in tennis, and I've been wanting to do it for a long time," Williams said of the outfit she wore despite a brisk change in the weather, with mostly cloudy skies and temperatures in the 60s. "The illusion of just having bare skin is definitely for me a lot more beautiful."

Top-ranked and returning champion Roger Federer also advanced, enduring one tense set and two rain delays before eliminating Alejandro Falla of Colombia, 7-6 (4), 6-2, 6-4, in the second round of the French Open on Wednesday.